ß-Thromboglobulin may not reflect platelet activation during haemodialysis with the HeprAN membrane.

BACKGROUND: When blood passes through the extracorporeal circuit during haemodialysis (HD) undesirable effects including platelet degranulation and coagulation activation take place. ß-thromboglobulin (ß-TG) is a sensitive marker of platelet activation. The aim of this study was to investigate platelet degranulation and coagulation activation during HD with the heparin-coated dialysis membrane HeprAN. METHODS: Four HD sessions were evaluated in each of 12 chronic HD patients. None of the patients used oral warfarin, other anticoagulants or antiplatelet drugs. In the first session the HeprAN membrane or a conventional polyflux membrane was used in a randomized manner and thereafter alternately in a cross-over design, and 50% of the conventional dalteparin dose was given at start of HD. Prothrombin fragment 1 + 2 (PF1 + 2), ß-TG and anti-factor Xa activity were measured repeatedly. RESULTS: No dialysis sessions were terminated early due to clotting of the extracorporeal system. Activation of intravascular coagulation as assessed by change in PF1 + 2 during 4 hours of HD was the same with the two membranes. ß-TG concentration decreased significantly during 4 hours of HD with the HeprAN membrane but remained stable with the polyflux membrane. CONCLUSION: There were no differences in clotting scores or coagulation activation with the two membranes. The decrease in ß-TG during HD with the HeprAN membrane suggests ß-TG to be an inferior marker of platelet degranulation when using a heparin-coated dialysis membrane. A possible mechanism for the decline in ß-TG concentration may be adherence of this heparin-binding protein to the heparin-coated dialysis membrane.

Low level of MAp44, an inhibitor of the lectin complement pathway, and long-term graft and patient survival; a cohort study of 382 kidney recipients.

BACKGROUND: Higher incidence of malignancy and infectious diseases in kidney transplant recipients is related to immunosuppressive treatment after transplantation and the recipient's native immune system. The complement system is an essential component of the innate immunity. The aim of the present study was to investigate the association of effector molecules of the lectin complement pathway with graft and patient survival after kidney transplantation. METHODS: Two mannan-binding lectin (MBL) associated proteases, MASP-2 and MASP-3 (activators of the lectin pathway) and two MBL-associated proteins, MAp44 and MAp19 (inhibitors of the lectin pathway) were measured at the time of transplantation in 382 patients (≥17 years old) transplanted in 2000-2001. The cohort was followed until December 31, 2014. Data on patient and graft survival were obtained from the Norwegian Renal Registry. Cox proportional hazard regression models were performed for survival analyses. RESULTS: Low MAp44 level (1st versus 2-4 quartile) was significantly associated with overall mortality; HR 1.52, 95 % CI 1.08-2.14, p = 0.017. In the sub analyses in groups below and above median age (51.7 years), low MAp44 as a predictor of overall mortality was statistically significant only in recipients of ≤51.7 years; HR 2.57, 95 % CI 1.42-4.66, p = 0.002. Furthermore, low MAp44 was associated with mortality due to infectious diseases; HR 2.22, 95 % CI 1.11-4.41, p = 0.023. There was no association between MASP-2, MASP-3 or MAp19 levels and patient mortality. No association between any measured biomarkers and death censored graft loss was found. CONCLUSIONS: Low MAp44 level at the time of transplantation was associated with increased overall mortality in kidney recipients of median age of 51.7 years or below and with mortality due to infectious diseases in the whole patient cohort after nearly 14-years of follow up after transplantation. No associations between other effector molecules; MASP-2, MASP-3 or MAp19 and recipient mortality were found, as well as no association of any biomarker with death censored graft loss.

The impact of early cytomegalovirus infection after kidney transplantation on long-term graft and patient survival.

This prospective observational cohort study is an extension of a previous study reporting effects of cytomegalovirus (CMV) on graft and patient survival in 471 patients who underwent kidney transplantation between 1994 and 1997. CMV pp65 antigen was measured every 7-14 d during the first three months after transplantation, given as number of CMV pp65-positive cells per 10(5) leukocytes. A positive test was defined as CMV infection. None of the patients received CMV prophylaxis or preemptive treatment. During a median of 13.7 (7.1-14.9) yr, the number of death-censored graft losses was 118 (25%) and of patient deaths 224 (48%). CMV infection was an independent significant risk factor for mortality in multivariate analysis (HR = 1.453, 95% CI 1.033-2.045, p = 0.032), adjusting for patient and donor age, preemptive transplantation, HLA-DR and -AB mismatches, living donor, acute rejection during the first three months, donor-recipient CMV IgG antibody status and diabetic nephropathy. In univariate analysis, CMV infection was significantly associated with death-censored graft loss but the association was not significant in multivariate model. CMV infection early after kidney transplantation is a predictor of overall mortality but not of death-censored graft loss after a median observation period of 13.7 yr.

Cellular immunity against cytomegalovirus and risk of infection after kidney transplantation.

Introduction: Cytomegalovirus (CMV) infection remains a challenge following kidney transplantation (KTx). Currently, CMV-IgG serostatus at transplantation is used to individualize CMV preventive strategies. We assessed the clinical utility of CMV-IGRA for predicting CMV infection following KTx. Methods: We performed a nationwide prospective cohort study from August 2016 until December 2022. Data from all adult KTx recipients in Norway, n=1,546 (R+; n=1,157, D+/R-; n=260, D-/R-; 129), were included with a total of 3,556 CMV-IGRA analyses (1,375 at KTx, 1,188 at eight weeks, 993 one-year after KTx) and 35,782 CMV DNAemia analyses. Results: In R+ recipients CMV-IGRA status, measured at any of the time-points, could not identify any differential risk of later CMV infection. D+/R- recipients remaining CMV-IGRA negative 1-year after transplantation (regardless of positive CMV DNAemia and/or CMV IgG status at that time) had increased risk of developing later CMV infection compared to D+/R- recipients who had become CMV-IGRA positive (14% vs. 2%, p=0.01). Conclusion: Knowledge of pre-transplant CMV-IGRA status did not provide additional information to CMV-IgG serostatus that could improve current post-transplant CMV treatment algorithms. However, D+/R- recipients with a persisting negative CMV-IGRA one-year after transplantation remained at increased risk of experiencing later CMV infection. Therefore we advocate post-transplant CMV-IGRA monitoring in these patients.

Cytomegalovirus High-risk Kidney Transplant Recipients Show No Difference in Long-term Outcomes Following Preemptive Versus Prophylactic Management.

BACKGROUND: Following kidney transplantation (KT), cytomegalovirus (CMV) infection remains an important challenge. Both prophylactic and preemptive antiviral protocols are used for CMV high-risk kidney recipients (donor seropositive/recipient seronegative; D+/R-). We performed a nationwide comparison of the 2 strategies in de novo D+/R- KT recipients accessing long-term outcomes. METHODS: A nationwide retrospective study was conducted from 2007 to 2018, with follow-up until February 1, 2022. All adult D+/R- and R+ KT recipients were included. During the first 4 y, D+/R- recipients were managed preemptively, changing to 6 mo of valganciclovir prophylaxis from 2011. To adjust for the 2 time eras, de novo intermediate-risk (R+) recipients, who received preemptive CMV therapy throughout the study period, served as longitudinal controls for possible confounders. RESULTS: A total of 2198 KT recipients (D+/R-, n = 428; R+, n = 1770) were included with a median follow-up of 9.4 (range, 3.1-15.1) y. As expected, a greater proportion experienced a CMV infection in the preemptive era compared with the prophylactic era and with a shorter time from KT to CMV infection ( P < 0.001). However, there were no differences in long-term outcomes such as patient death (47/146 [32%] versus 57/282 [20%]; P = 0.3), graft loss (64/146 [44%] versus 71/282 [25%]; P = 0.5), or death censored graft loss (26/146 [18%] versus 26/282 [9%]; P = 0.9) in the preemptive versus prophylactic era. Long-term outcomes in R+ recipients showed no signs of sequential era-related bias. CONCLUSIONS: There were no significant differences in relevant long-term outcomes between preemptive and prophylactic CMV-preventive strategies in D+/R- kidney transplant recipients.

A heparin-coated dialysis filter (AN69 ST) does not reduce clotting during hemodialysis when compared to a conventional polysulfone filter (F×8).

BACKGROUND: We investigated whether the heparin-coated AN69 ST hemodialysis (HD) filter induced less hypercoagulability during HD than a conventional polysulfone filter (F×8). METHODS: In a crossover design, 11 patients were treated alternately with AN69 ST and F×8 filters (45 sessions). All filters were primed with unfractionated heparin (UFH) and unadsorbed UFH was removed by saline flushing. Half the conventional dalteparin dose was given as a bolus dose at the start of HD. Clotting was evaluated hourly in the venous air trap. Prothrombin fragments 1 and 2 (PF1 + 2), antithrombin (AT), ß-TG and anti-FXa activity were repeatedly measured. RESULTS: One patient treated with enalapril had two repeated adverse reactions to the AN69 ST filter and was excluded from the study. Use of the AN69 ST filter did not decrease the mean clot score or PF1 + 2, but decreased ß-TG compared to the F×8 filter. CONCLUSION: The heparin-coated AN69 ST filter did not induce less coagulation when compared to the F×8 filter.

Impact of the complement lectin pathway on cytomegalovirus disease early after kidney transplantation.

BACKGROUND: This study retrospectively investigated the association between pre-transplant levels of mannose-binding lectin (MBL) plus the associated serine protease (MASP)-2 and the occurrence of cytomegalovirus (CMV) infection and symptomatic CMV disease during the first 12 weeks after kidney transplantation. Materials and methods. Altogether 159 consecutive single kidney transplant recipients were included. The patients were screened for CMV pp65 antigenaemia every second week. No CMV prophylaxis or pre-emptive treatment was given. MBL and MASP-2 were measured in samples taken at transplantation and 10 weeks later. RESULTS: CMV infection, defined as at least one positive test, was found in 95 patients (59.8%). MBL and MASP-2 measured at transplantation were similar in patients with and without CMV infection. The incidence of CMV infection was also similar in 36 patients (58.3%) with pre-transplant MBL levels below the reference level (500 microg/L) and in patients with higher MBL levels (60.2%). Symptomatic CMV disease was diagnosed in 35 patients (22%), and MASP-2 levels at transplantation in the lower quartile range (

The natural course of cytomegalovirus infection and disease in renal transplant recipients.

A series of prospective studies of a large cohort population of renal transplant recipients who did not receive cytomegalovirus (CMV) prophylaxis or preemptive therapy examined the effects of CMV infection and disease on renal allograft rejection, long-term recipient and graft survival, and new-onset diabetes mellitus. CMV infection and disease were found to be independent risk factors for allograft rejection and new-onset diabetes mellitus within 100 days posttransplantation, and for recipient mortality and uncensored graft loss beyond 100 days posttransplantation. Additional studies are needed to determine whether CMV prophylaxis or preemptive therapy may be of benefit in preventing these complications.

High ficolin-3 level at the time of transplantation is an independent risk factor for graft loss in kidney transplant recipients.

BACKGROUND: Recent studies have shown that activation of the complement system may be associated with long-term graft function. The aim of this retrospective study was to assess the impact of the pattern recognition molecules of the lectin pathway on long-term graft survival after kidney transplantation. METHODS: Patients transplanted in 2000 to 2001 were included. Mannose-binding lectin, Ficolin-1, and Ficolin-3 were measured in serum at the time of transplantation. Data on death-censored graft loss were obtained from the Norwegian Renal Registry. Competing risks regression was used to investigate the association between time to graft loss and the explanatory variables. The variables were: high Ficolin-3 (upper quartile, ≥33.3 µg/mL) versus low Ficolin-3 (<33.3 µg/mL), acute rejection (time-dependent), age, basiliximab induction, sex, donor age, human leukocyte antigen mismatches, human leukocyte antigen antibodies, cold ischemia time, living donor, and preemptive transplantation. RESULTS: A total of 382 patients with a median follow-up of 9.8 years were included. Sixty-six patients (17%) had death-censored graft loss, and 116 (30%) patients died. In a final competing risks model, high Ficolin-3 (subhazard ratio [SHR] = 1.95, P = 0.009), acute rejection (one vs. none) (SHR = 1.93, P = 0.033), acute rejection (two vs. none) (SHR = 5.45, P < 0.001), and age (SHR = 0.98, P = 0.006) were associated with death-censored graft loss. Basiliximab induction was associated with improved graft survival (SHR = 0.50, P = 0.016). No associations between mannose-binding lectin or Ficolin-1 and graft loss were found. CONCLUSION: High Ficolin-3 level at the time of transplantation was an independent significant risk factor for shorter graft survival, even when adjusted for other covariates.

Effects of Hemodialysis on Methadone Pharmacokinetics and QTc.

PURPOSE: Effects of hemodialysis on pharmacokinetic properties and QTc were studied in 4 patients taking daily methadone dose of 100 mg (range, 60-120 mg). METHODS: Methadone in serum, dialysate, and urine were measured by LC-MS/MS. QTc was calculated with Bazett's formula. FINDINGS: The serum Cmin methadone level was 1124 nmol/L (range, 547-1581 nmol/L). Methadone dialysate clearance was 17.1 mL/min (range, 13.7-20.6 mL/min). Total loss in dialysate was 2.30% (range, 1,25-3,70%) of daily methadone intake. QTc increased from 391 msec (range, 369-406 msec) to 445 msec (range, 407-479 msec), independently of serum methadone level, which may be explained by normalization of serum electrolytes. IMPLICATIONS: Methadone dose adjustment is not needed because of hemodialysis.

Low molecular weight heparins as thromboprophylaxis in patients undergoing hemodialysis/hemofiltration or continuous renal replacement therapies.

Low molecular weight heparins (LMWHs) have potential advantages over unfractionated heparin (UFH). They interact less with platelets and may induce less bleeding. The risk for heparin induced thrombocytopenia is less, and the effect on serum lipids is favourable. The half-life is longer, allowing for one single bolus dose at start of hemodialysis (HD). In addition, LMWH is found to result in lower plasma potassium in HD patients compared to UFH. LMWHs have an established role in HD and hemofiltration (HF), but the reports on their efficacy and safety during continuous renal replacement therapy (CRRT) are scarce.

Cytomegalovirus infection in renal transplant recipients is associated with impaired survival irrespective of expected mortality risk.

Cytomegalovirus (CMV) infection and CMV disease are associated with increased mortality post-transplantation. We have thus retrospectively examined whether this association is found both in patients with high and low mortality risk. Between 1994 and 1997, 471 kidney transplant recipients were monitored once weekly for CMV pp65 antigenemia and CMV disease the first 100 d after tx and followed prospectively for median 66.6 months. Patients with nephrosclerosis, diabetic nephropathy and amyloidosis were selected as high mortality risk groups (HRG). Overall and cardiovascular mortality beyond 100 d in the low-risk group (n = 372) was 14% and 3.5%, and in the HRG (n = 99) 31% and 16%, respectively. The effects of CMV infection and disease, recipient age and gender, panel-reactive cytotoxic antibodies, acute rejection, HRG, and graft loss in the whole study period were tested on overall mortality beyond 100 d in multiple analysis. HRG was independently associated with overall mortality, RR = 2.03, and still both CMV infection and disease were significant risk factors for mortality, independent of HRG. The same analysis was repeated for HRG (n = 99). Even in this small group CMV disease was independently associated with overall mortality. These data indicate that CMV increase mortality independently both in patients with otherwise high- or low-risk for long-term mortality.

Intermittent saline flushes during haemodialysis do not alleviate coagulation and clot formation in stable patients receiving reduced doses of dalteparin.

BACKGROUND: Heparin-free haemodialysis (HD) with intermittent saline flushes (ISF) in patients with bleeding risk is widely used. The aim of this study was to investigate if ISF reduce coagulation and clotting in stable patients receiving reduced doses of dalteparin. METHODS: Inclusion criteria were stable chronic HD patients >or=18 years of age and haemoglobin >or=11 g/dl. Exclusion criteria were use of warfarin and acetylsalicylic acid. Six HD sessions were evaluated per patient. Dalteparin was given as one bolus dose at start of HD (50% of the conventional dose). In HD number 1, 3 and 5, 100 ml saline solution was flushed through the filter each 30 min. In HD 2, 4 and 6, no ISF were given. Potential clotting in the bubble trap was visually observed each hour and graded on a 4-point scale: 1 = normal, 2 = fibrinous ring, 3 = clot formation and 4 = coagulated system. The dialyser was visually inspected at the end of each session: 1 = normal, 2 = a few blood stripes (affecting less than 5% of the surface fibres), 3 = many blood stripes (more than 5% of the fibres) and 4 = coagulated filter. The coagulation marker PF1+2, the platelet activation marker beta-TG and anti-FXa activity were repeatedly measured during HD. RESULTS: Six men and two women were included. In four cases (four different patients), HD was stopped due to a coagulated system, all cases on days with ISF performed. Multiple linear regression analyses with repeated measurements showed that ISF adjusted for dalteparin dose/kg significantly increased mean clot in the bubble trap, estimate (B) = 0.717, P = 0.0001 and also showed that ISF increased PF1+2, B = 0.16, P = 0.001 when adjusted for anti-FXa activity and hours of dialysis, whereas beta-TG was only borderline increased, B = 0.09, P = 0.055. CONCLUSIONS: ISF during HD does not alleviate visible clotting or intravascular coagulation activity in stable patients receiving reduced doses of dalteparin and polysulphone dialysers. Whether this applies to unstable patients with increased bleeding risk not receiving any anticoagulation remains to be shown.

Early posttransplant serum osteoprotegerin levels predict long-term (8-year) patient survival and cardiovascular death in renal transplant patients.

The primary objectives of this analysis were to examine the effects of early posttransplantation (10 wk) serum levels of osteoprotegerin (OPG), mannose-binding lectin (MBL), and MBL-associated serine proteases (MASP; MASP-2 and MASP-3) on long-term (8-yr) patient survival, graft survival, and cardiovascular (CV) death. During a period of 16 mo (1995 to 1996), a total of 173 consecutive renal transplant recipients without diabetes before transplantation were included in a prospective study that was designed to address the impact of metabolic CV risk factors on survival and CV end points. Baseline sera from 172 patients were available for analysis. Follow-up data until January 1, 2004, were obtained from a national renal registry. Patients with high (fourth quartile) serum levels of OPG had significantly higher all-cause mortality (hazard ratio [HR] 6.3; 95% confidence interval [CI] 3.3 to 11.8; P<0.001) and CV death (HR 10.8; 95% CI 3.8 to 30.4; P<0.001) than patients with lower OPG concentrations. After multiple Cox regression analysis, high serum levels of OPG remained an independent predictor of all-cause mortality (HR 6.0; 95% CI 3.1 to 11.6, P<0.001) and CV death (HR 8.2; 95% CI 2.5 to 26.4; P<0.001). Multiple linear regression analysis revealed that age, creatinine clearance, and high-sensitivity C-reactive protein all were independently associated with OPG (R2=0.42). No significant association between OPG and death-censored graft loss was revealed. Serum levels of MBL, MASP-2, and MASP-3 were not significantly associated with patient survival, CV death, or graft loss. Early measured posttransplantation serum OPG is a highly significant independent predictor of death from any cause or CV death in white renal transplant recipients.

Effect of immune modulation on TT virus (TTV) and TTV-like-mini-virus (TLMV) viremia.

The present study was designed to investigate how two chronically replicating viruses, TT virus (TTV) and TTV-like mini virus (TLMV), interact with host defence systems. Successive serum samples from three groups of subjects, undergoing modifications of their antiviral defence, were tested by real-time PCR to measure changes in viral titers, and by sequence analyses to indicate whether increases in viremia could be attributed to infection with an unfamiliar strain: 1) in patients receiving immunosuppressants subsequent to kidney transplantation, viral titers tended to increase; 2) in soldiers undergoing extreme training known to cause immunosuppression, insignificant increases in titers were observed; and 3) interferon treatment of patients with hepatitis C virus caused a temporary decrease in TTV and TLMV titers. Increases in viremia were associated only occasionally with the appearance of novel strains. The above results add to knowledge on how these viruses are influenced by the host.

The impact of cytomegalovirus infection and disease on rejection episodes in renal allograft recipients.

Cytomegalovirus (CMV) infection and disease are potential risk factors for acute allograft rejection in renal transplant recipients. The present study specifically addresses this issue. From October 1994 to July 1997, 477 consecutive renal allograft recipients (397 first transplants and 80 retransplants) were included in the study. CMV infection (cytomegalovirus pp65 antigen in leukocytes) and disease (infection and clinical symptoms or signs of disease) were examined prospectively for 3 months. No CMV prophylaxis was given, and CMV disease was treated with intravenous (i.v.) ganciclovir. The retransplantation of four patients transplanted twice during the study and 22 patients receiving kidneys from human leucocyte antigen (HLA)-identical siblings were excluded from statistical analysis. Rejections were evaluated clinically [277(61%)] and 173 (38%) also had a biopsy verified rejection. CMV infection occurred in 64% of the patients and 24% experienced CMV disease. In a multiple time-dependent Cox analysis, CMV infection and CMV disease were independent significant predictors for clinical acute rejections, RR = 1.6 (1.1-2.5, p = 0.02) and RR = 2.5 (1.2-5.1, p = 0.01), respectively. Among 173 patients with biopsy verified rejection, 72% of the patients had tubulointerstitial rejection whereas 28% had a vascular rejection. CMV disease, but not CMV infection was a predictor of tubulointerstitial rejection, RR = 3.1 (1.1-9.3, p = 0.04). CMV infection and disease are independent risk factors for clinical acute rejection in kidney allograft recipients. CMV disease is an independent risk factor for biopsy verified acute tubulointerstitial rejection in kidney allograft recipients.

Impact of early cytomegalovirus infection and disease on long-term recipient and kidney graft survival.

BACKGROUND: The impact of cytomegalovirus (CMV) infection and disease on long-term outcome after kidney transplantation is still unsettled. METHODS: Between 1994 and 1997, 397 consecutive first kidney graft recipients and 74 retransplants were included in the study and followed prospectively until December 31, 2001. CMV infection (CMV pp65 antigenemia) and CMV disease were recorded once weekly during the first 100 days after transplantation. No CMV prophylaxis or preemptive therapy was given. In a multiple Cox proportional hazard model allowing time-dependent covariates, the effects of asymptomatic CMV infection and CMV disease, recipient age and gender, retransplantation, living donor, panel-reactive cytotoxid antibodies, acute rejection, and graft loss were tested on overall mortality beyond 100 days post-transplantation. In a similar analysis, the effect of asymptomatic CMV infection and CMV disease plus other factors were tested on death censored graft loss beyond 100 days. RESULTS: Median (range) follow up time was 66.6 (<1-86.9) months. The incidence of CMV infection and disease during the first 100 days was 62.8% and 23.4%, respectively. The number of total deaths was 96 (20%), 82 occurred after the first 100 days. Independent risk factors for overall mortality beyond 100 days were asymptomatic CMV infection, RR = 2.90 (95% CI 1.61-5.22) (P= 0.001), CMV disease, RR = 2.50 (95% CI 1.31-4.79) (P= 0.006), both compared to no infection or disease, recipient age, RR = 1.066 per year (95% CI 1.048-1.084) (P < 0.001), and graft loss in the whole study period RR = 7.88 (95% CI 4.75-13.08) (P < 0.001). Asymptomatic CMV infection and CMV disease were not independent risk factors for death censored graft loss, but they significantly reduced graft survival uncensored for death, (log rank P= 0.001, respectively). CONCLUSION: Asymptomatic CMV infection and overt CMV disease during the first 100 days increase the risk of recipient mortality beyond 100 days. This raises the question whether CMV prophylaxis should be given routinely after kidney transplantation.

Pre-emptive therapy of CMVpp65 antigen positive renal transplant recipients with oral ganciclovir: a randomized, comparative study.

BACKGROUND: About one-quarter of renal transplant patients will suffer from symptomatic cytomegalovirus (CMV) disease if no preventive therapeutic measures are taken. In this prospective, randomized single-centre study pre-emptive therapy with oral ganciclovir is compared with conventional deferred treatment. METHODS: Renal transplant recipients (n= 455) over 18 years of age were screened weekly for CMV pp65 antigenaemia during the first 12 weeks post-transplantation. If CMV pp65 antigen in leukocytes appeared within 8 weeks post-transplantation patients were randomized and included in the study. Five patients developed CMV disease before positive CMV pp65, and 14 patients with a positive antigen test developed CMV disease before randomization could take place, all these representing a limitation of the applicability of the results in the overall renal transplant population. Altogether 179 patients were not randomized for various reasons. Eighty patients completed the study, 42 were randomized to receive pre-emptive oral ganciclovir therapy and 38 to conventional deferred treatment (control group). RESULTS: Time from transplantation to start of ganciclovir capsules was 36 (12-60) days and duration of oral ganciclovir therapy was 49 (27-70) days, median (range). No patient in the pre-emptive treatment group, but nine of 38 patients (23.7%) in the control group, developed CMV disease during the first 12 weeks post-transplantation (P= 0.0009). In the period from 3 months to 1 year post-transplantation, two patients in each group developed CMV disease. There were no significant differences in acute rejection or renal function between treatment groups during the first post-transplant year. CONCLUSIONS: Pre-emptive oral ganciclovir therapy in renal transplant recipients during the first 12 weeks post-transplantation effectively prevents CMV disease during this time period. The incidence of late CMV disease (3 months to 1 year after transplantation) was similar in the two groups, indicating that pre-emptive therapy does not result in late onset of CMV disease.